This invention relates to a snap-action device for cooperating with toothed wheels, in particular for use in change-over or other electrical switches or the like.
Electrical change-over switches usually comprise a shaft for shifting the contact unit, this shaft being connected to a toothed wheel. This latter cooperates generally with two opposing pawls, each loaded by a spring.
The usual pawls generally have a substantially U-shaped profile and rest with their base on horizontal guides which also act as the support for the loading spring.
Said pawls are very difficult to mount. To do this, the spring has to be preloaded, then inserted into the appropriate seat for the pawl and the pawl finally positioned on the guides along which it slides.
The small dimensions of the elements which have to be handled make these operations even more complicated. In addition, after the pawl has been correctly mounted and positioned, if the pawl is accidentally knocked or if the toothed wheel is not inserted correctly, it can escape from its housing seat urged by the spring, in which case it has to be remounted.